Fishdom H2O: Hidden Odyssey is the sequel to Fishdom, but abandons the match-3 gameplay for a very different hidden object experience. Like the original, you get to buy fish and decorate three exotically themed fish tanks, trying to keep your fish happy and your tanks beautiful.

You play as Jennifer, a marine biology student from the Environmental Protection University. It's her last summer as a student and she's determined to get a job at Old Barney's Aquarium, the largest marine conservation center in the world. Old Barney won't hire just anyone though, and will only hire Jennifer if she can pass a trial period. Luckily for Jennifer, her Grandpa Jack is a famous oceanographer, and he's happy to guide her along the way.

Jennifer knows she can create an excellent aquarium, but a lack of cash flow means she can only afford one fish. In order to earn more money to build up her aquarium, she decides to go deep sea diving, collecting all kinds of "junk" at the bottom of the sea. And you know what that means -- it's time for hidden object gameplay!

For each hidden object round, you'll be given a list of items to find among the underwater scene. The items are fairly typical hidden object fare, including assorted oddities like sweaters, pearls, guitars, and other things that would probably classify the water as polluted. All of the items are clearly drawn, so it's a pleasure to find them. Things consistently look like they should, so there isn't too much guess work involved. Of course, this makes the game play a bit easier, but since the scenes are suitably cluttered, it's not without challenge.

Most of the time, objects are named, but occasionally you'll get a simple clue, like "puts out fires" for an extinguisher. Sometimes you'll be asked to find a number of the same items, like ten Greek vases. There are also special "Gold Rush" levels, where you're given 30 seconds to gather up as many gold items as you can. Not all gold rush items sparkle, and some are covered with ooze that makes them harder to spot. Quick eye rounds give you 15 seconds to find one of three items on a list.

The game offers timed or relaxed modes, although the timer doesn't really count for much. If you don't click on anything for a while, an item will sparkle to get your attention. You have just 3 minutes to find everything on your list. If you take too long, you'll run out of air and resurface with less cash, but there's no other penalty.

Too many random clicks can wake up a school of goldfish that make a mess of bubbles across the screen, obscuring the hidden objects from view. If you need a hint, you can click the seahorse jar, which releases a seahorse that stands next to a hidden object on your list. You can earn extra hints by finding extra seahorses in the hidden object scenes.

You can use the cash you earn to buy fish and items to keep your fish happy. Just like in the first Fishdom, there are three bars at the top, each measuring the progress of your tank's fish, beauty, and comfort. The fish gives you hints about what they'd like, shown as thought bubbles over their heads.

Items to increase the tank's beauty include plants, shells, coral, and ornaments (over 30 for each tank tank). You can position these items anywhere you like, and can move them around at any time. Comfort items include lights, air pumps, filters, and temperature regulators (8 for each tank). There are 20 different fish to buy, including lionfish, pipefish, clownfish and other aquatic animals like green sea turtles.

You can earn two types of trophies for each aquarium. A star trophy (given if all three stats reach 100%) will allow you to unlock a new tank, but you can keep improving your old tank in order to earn a cup trophy. The game also comes with a screensaver, which you can turn on and off from inside the game. The screensaver reflects your progress in the game, so you can see the actual plants and fish that you've earned.

The length is great, although much of it comes from playing the hidden object rounds repeatedly. There are no set levels, so it's all about earning cash to buy more goodies for your tanks. It takes roughly 1 1/2 hours to complete a tank with a star score, and there are 3 tanks to complete, so you can expect to play 4-5 hours before you complete the basics. That's not counting replay value if you go back and aim for the cup trophies, which easily pushes the game into the 9-10 hour range.

On the whole, it has good production values, complete with polished art, smooth game play, and voice overs during the cutscenes. It's a lot of fun to play, although to be fair, there are other more in-depth fish raising sims out there, like FishCo, or Fish Tycoon. There are over 30 different beauty items for each tank, but it still would have been nice to have more. As for the hidden object scenes, they do vary slightly, but not much. The backgrounds are limited to the same underwater scenes, over and over. However, there are many objects to find (over 1,000), so it doesn't feel too repetitive.

Fishdom H2O: Hidden Odyssey is a very different game than its predecessor. If it weren't for the common fish tank theme, it would seem they were completely unrelated. It's not a match-3 game, so match-3 fans and those who enjoyed the original might be disappointed. However, on its own, it's a fun fish tank decorating game with interesting (albeit simple) hidden object game interludes.